Syria: government troops participate in a live fire exercise. Activists say more than 200 people have been killed in a massacre in Hama province. Photograph: AP

Syrian government troops and a pro-regime militia have killed more than 200 people, mostly civilians, in a village near the city of Hama, opposition activists reported in the early hours of Friday morning.

The massacre is said to have taken place in the village of Tremseh, starting early Thursday morning, when government forces are alleged to have surrounded the village and opened fire with mortars and artillery. Then an Alawite pro-government militia, the Shabiha, are reported to have moved into Tremseh and started carrying out executions.

A statement by the Hama Revolutionary Council said: "More than 220 people fell today in Tremseh. They died from bombardment by tanks and helicopters, artillery shelling and summary executions.

"It appears that Alawite militiamen from surrounding villages descended on Tremseh after its rebel defenders pulled out, and started killing the people. Whole houses have been destroyed and burned from the shelling," Fadi Sameh, an opposition activist from Tremseh, told Reuters.

Sameh said he had left the town before the reported massacre but was in touch with residents.

"Every family in the town seems to have had members killed. We have names of men, women and children from countless families," he said, adding that many of the bodies were taken to a local mosque.

Reuters also quoted an activist from the Union of Hama Revolutionaries, Ahmed, as saying: "We have reports of more than 220 killed. So far, we have 20 victims recorded with names and 60 bodies at a mosque. There are more bodies in the fields, bodies in the rivers and in houses … people were trying to flee from the time the shelling started and whole families were killed trying to escape."

It was impossible to confirm the reports immediately, in part due to the state ban on foreign and independent journalists, but if confirmed, the killings would represent the single biggest massacre in 16 months of the Syrian revolt.

Syrian state television reported that three security personnel had been killed in fighting in Tremseh and reported a massacre, but blamed it on "armed terrorist groups".

Earlier in the evening, the London-based Syrian Observatory for Human Rights, told the French Press Agency that government bombardment had killed over 100 people, although only 30 at that point had been identified.

"Government troops bombarded the village using tanks and helicopters," the Observatory director, Rami Abdel Rahman, said.

Al-Jazeera's correspondent, Rula Amin, reporting from Beirut, said: "We're hearing from activists that it started at 5am this morning, when the village was surrounded by government forces and pro-government militias. Bodies were found of people killed by knives, and some bodies burnt. But exactly what happened is still not very clear."

Human rights activists put the death toll since the revolt broke out last March at 17,000. The biggest single massacre confirmed so far was in Houla province in May, in which 108 people were killed, including 49 children and 34 women.

Survivors told the Guardian that the killings in that case had been carried out by the Shabiha militia. A UN investigation also pointed to evidence of Shabiha involvement.

The new reports of a massacre came as members of the UN security council in New York debated rival drafts of resolutions intended to help stop the bloodshed.

A UK-sponsored draft being circulated calls for sanctions to be imposed on the Assad regime if it does not withdraw its troops from major towns to their barracks in 10 days. A rival Russian draft does not threaten any punitive measures.

It is 30 years since President Bashar al-Assad's father, Hafez, oversaw the killings of tens of thousands of Sunnis in Hama, when he sent troops to crush an uprising by the Muslim Brotherhood.